package com.codeforces.contest.c25;

import java.util.Scanner;

public class _25B {

	static Scanner scanner = new Scanner(System.in);
	static int n;
	static String s;

	public static void main(String[] args) {
		n = scanner.nextInt();
		s = scanner.next();
		for (int i=0;i<s.length();) {
			if (i + 3 == n) {
				System.out.println(s.substring(i));
				i += 3;
			}
			else {
				if (i + 2 == n) {
					System.out.println(s.substring(i));
				}
				else {
					System.out.print(s.substring(i, i+2) + "-");
				}
				i += 2;
			}
		}

	}

}
